The present invention relates to ribbon cartridges and in particular, ribbon cartridges of the type having a body portion wherein an endless ribbon is contained in a fanfold condition during use.
Ribbon cartridges of this type have been used in increasing numbers especially in point of sales machines wherein continuous use is required with infrequent ribbon changes, conditions which are met by endless fabric ribbons stored in cartridges.
As will be explained in more detail with respect to FIG. 1, prior art ribbon cartridges of this type are initially provided with an endless ribbon rolled up in a spool and which after repeated use in a printer, works itself into the fan-folded state similar to that shown in FIG. 2. However, due to the fact that the ribbon cartridge must be provided with a substantially large aperture in one main wall thereof in order to allow for the driving of the ribbon during use, it is important that the ribbon not approach the drive aperture so as to prevent the inadvertent removal of the ribbon therethrough.
In the prior art, a removable cardboard member is provided which has arms extending through the drive aperture and which bears against the ribbon spool to prevent its falling through the drive aperture.
The disadvantage of the prior art device is that it is flimsy in construction and is suitable only for holding the ribbon when in a wound configuration. Further, the use of the ribbon in the initial wound state is found to jam-up during its transformation from the wound state to the fan-folded state and thus, while it is more desirable to initially provide the ribbon in the fan-folded state, it is impossible to do so with the construction in the prior art.